The present invention relates to a restraining element, or restraint system, which has a plurality of restraint devices for vehicle passengers and is equipped with a central control unit that via a bus system controls the tripping of the restraint devices.
One such restraint system is described in the printed proceedings of the third International Symposium on Sophisticated Car Occupant Safety Systems, "Airbag 2000", Karlsruhe, Germany, Nov. 26-27, 1996, pages 16-1 through 16-19. As can be learned from this paper, there have already been frequent cases in which vehicle passengers have been even fatally injured by an inflated air bag. As a rule, this was due to the fact that the restraint systems used in the past have been very rigid in their tripping behavior and cannot react flexibly to different types of seat occupation and to various seat positions and passenger body sizes or weights. Professionals in the field have therefore proposed the introduction of so-called intelligent restraint systems, which make it possible for the restraint devices (such as air bags) not to be tripped with full force in every instance, but instead to be tripped with reduced force or in succession in multiple stages, depending on the severity of the accident and on the seat occupation. An intelligent restraint system of this kind should also be able to tell whether a particular type or severity of accident, or a particular kind of seat occupation (child seat), is involved in which tripping should be omitted entirely. An intelligent restraint system should also be capable, in multiple collisions, to react with multiple tripping of the various restraint devices.
In the literature cited above, it is proposed that given the many restraint devices built into vehicles in the future (air bags in the head, thorax and knee region for every vehicle passenger, and belt tighteners), all the restraint devices be triggered from a central control unit via a so-called "firing bus". Every restraint device is provided with a gas generator, which receives its firing information from the central control unit via the firing bus.
The object of the invention is to disclose a restraint system of the type defined at the outset which at the least possible expense enables very flexible triggering of each individual restraint device, so that depending on the type of accident, the severity of the accident, and the seat occupation (such as the passenger position and passenger weight), optimal protection for the passengers is assured.